Volcanism, Sedimentation, and Hydrothermal activity in Santorini, Greece

Volcanic arcs are very important in terms of their impact on society since they are usually densely populated and thus pose a high risk (Sigurdsson, 2015). Santorini is considered one of the most violent and famous volcanoes in the world (Varnavas and Papavasiliou, 2020). It is the most active hydrothermal centre of the Hellenic Volcanic Arc in the Aegean Sea. The central and eastern sectors of the arc are characterized by large stratovolcanoes with caldera structures (Santorini) whilst the western part has mainly small, monogenic eruptive centres. Both subduction and extension occurs in the arc whereby the associated volcanism is thought to result from the subduction of the African lithosphere beneath the Aegean microplate (Varnavas and Papavasiliou, 2020). Though activity is considered to have begun in the late Pliocene, most of it is Quaternary (Druitt et al., 1999).

Santorini has a caldera structure created by multiple collapse events, one of which is the famous so-called Minoan eruption of ca. 1650 BCE, which covered neighbouring lands with thick tephra and caused tsunamis. Two volcanic islets, Palea Kameni and Nea Kameni (the Kameni Islands), were progressively formed in the middle of the caldera between 197 BCE and 1950 CE (Tarchini et al., 2019). Santorini magmas range from basaltic to rhyolitic and evidence of magma mixing is common, as [is the case(?)] for many arc magma systems (Druitt et al., 2019).